Analyzing system

ABSTRACT

In an analyzing system including a commanding unit for sending a command and an executing unit for executing a processing upon receiving the command, a processing instruction may not be executed at the right time due to a heavy traffic of information and other factors. In order to solve this problem, in a preparative separation system  1  according to the present invention, a PC  20  provides the execution time for starting/finishing the fractionation processing to a controller  18.  Therefore, even in the case where the time of the PC  20  and that of the controller  18  are not synchronized, the controller  18  can accurately set the execution time for starting/finishing the fractionation in a preparative separation unit  16.  A piping  17  may be placed so that the traveling time of sample components is sufficiently larger than the delay time of signals due to the signal transfer lag and other reasons. This can absorb the delay time, allowing the units to cooperate with each other at a correct timing.

TECHNICAL FIELD

The present invention relates to an analyzing system including a unitfor sending a command and a unit for performing, upon receiving thecommand, a predetermined processing.

“Analyzing systems” mentioned in the present invention may have any kindof structure and configuration as long as they have a function formeasuring a physical quantity or physical quantities of a sample to bemeasured.

BACKGROUND ART

Generally, an analyzing system such as a liquid chromatograph analyzingsystem is not composed of only an analyzing unit which has a liquidsupplier, a column, a detector, and other units. It is usually acombination of a plurality of units including an analyzing unit, acontrol unit for controlling the analyzing unit, a data processing unitfor receiving the signals provided from a detector and analyzing themand for creating a chromatogram with the elapsed time assigned to thehorizontal axis and the relative signal intensity to the vertical axis(for example, refer to Patent Document 1).

Configuring the system by combining independent units as in theaforementioned case facilitates the maintenance of each unit, comparedto the system in which all the units are unified. In addition, with thisconfiguration, it is relatively easy to combine different kinds ofunits. This has the advantage that the configuration of the product canbe easily modified to suit the needs of the user. Furthermore, as longas the units are connected to each other, each unit composing theanalyzing system can be placed in physically different places.

In the case where a plurality of units are included in an analyzingsystem and they cooperate to perform some kind of processing, one unitamong them functions as a commanding unit and another unit functions asan executing unit so as to cooperate with each other to perform theprocessing. For example, in a preparative separation system in which asample separated by a chromatograph is fractionated into components, afractionation operation is performed by the cooperation of a detectorfor detecting the sample components eluted from the chromatograph and acontrol unit for instructing, upon receiving the detection signal, apreparation unit to fractionate the sample. In an overlap injection datacollection system in which a next sample is injected while one sample isbeing analyzed by a chromatograph, multiple units cooperate with eachother. Such units include a detector for detecting the sample componentseluted from the chromatograph, a data processing unit for performing,upon receiving the detection signal, a data processing such as a peakdetection and analysis, and a control unit for providing an instructionfor injecting a sample into the chromatograph.

BACKGROUND ART DOCUMENT Patent Document

[Patent Document 1] JP-A 2004-101198

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention

In any conventional analyzing apparatus, a unit for providing aninstruction sends the instruction to an execution unit at the point intime when the execution unit executes the operation indicated by theinstruction. For example, in the case of the preparative separationsystem, which has been previously described as the first example, thecontrolling unit sends a fractionation initiation signal and afractionation termination signal respectively at the point in time whenthe preparative separation unit starts and finishes the fractionationprocess. In the case of the overlap injection data collection system,which has been previously described as the second example, the dataprocessing unit receives a data processing initiation signal from thechromatograph at the point in time when the next sample is injected intothe chromatograph, and starts a data processing relating to the sample.

However, sending an instruction at the point in time of processexecution as just described has a variety of problems. For example, inthe case of the aforementioned preparative separation system, thecontrolling unit receives a detection signal from the detector,determines the point in time of starting/finishing the fractionationbased on the level of the detection signal, the shape of an upslope ordownslope, and then sends out an operation instruction. In thisoperation, the initiation or termination of the fractionation in thepreparative separation unit may not be performed at the correct time(i.e. the precise point in time when the component to be analyzedarrives at the preparative separation unit) because the period of timerequired to receive the detection signal from the detector and that tosend an operation instruction to the preparative separation unit are notconstant depending on the state of the load of the entire system and thecommunication traffic.

In the case of the overlap injection data collection system, the dataprocessing unit performs a series of data processing operations for onesample: e.g. creating a data file, collecting the data, saving the datafile, analyzing the data, and outputting a report. However, starting adata processing of the next sample while performing a data-processing ofthe current sample complicates the processing flow and places greatstress on the CPU.

Means for Solving the Problem

To solve the aforementioned problem, the present invention provides ananalyzing system including:

a commanding unit for sending a command; and

an executing unit for, upon receiving the command, executing aprocessing, wherein

the commanding unit computes a shift time which is a difference betweena predetermined base-point time in the executing unit and an executiontime of the processing for which the command is sent to the executingunit, and sends the computed shift time with the command for theprocessing to the executing unit, and

the executing unit executes, at a point in time before or after thebase-point time by the shift time, the processing indicated by thecommand received with the shift time.

In the analyzing system according to the present invention, thecommanding unit instructs the execution unit to execute a processing,designating a relative time (i.e. the shift time). The shift time may bea positive value or a negative value. The execution unit computes thepoint in time by adding the shift time to the base-point in time andthen executes the instructed processing at the computed point in time.The computed point in time will be after the base-point time in the casewhere the shift time is a positive value, while it will be before thebase-point time in the case where the shift time is a negative value.

Determining the point in time when a processing is executed in theexecution unit by taking into account the shift time from the base-pointin time of the execution unit as just described allows the executionunit to accurately set the execution time of the instructed processingeven if the time of the commanding unit and that of the execution unitare not synchronized. In addition, using a sufficiently long shift timecan eliminate the possibility of being affected by the signalcommunication delay and other factors.

In the analyzing system according to the present invention, a processinginstruction is provided to the execution unit designating the executiontime of the processing. Therefore, a variety of processings may beexecuted in a distributed manner by the execution unit. This decreasesthe load on the CPU of the execution unit.

Effects of the Invention

With the present analyzing system according to the present invention,the commanding unit instructs the execution unit to execute aprocessing, designating a relative time. Hence, even in the case wherethe time of the commanding unit and that of the execution unit are notsynchronized, the execution unit can accurately set the point in timewhen the instructed processing is to be executed. In addition, with thepresent analyzing system according to the present invention, it ispossible to eliminate the influence of a signal communication delay andother factors and execute a variety of processings in a distributedmanner in the control unit and the data processing unit. This allowsmore flexible system design.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram of the main components ofthe first embodiment of the analyzing system according to the presetinvention.

FIG. 2 is a schematic configuration diagram of the main components ofthe second embodiment of the analyzing system according to the presetinvention.

FIG. 3 is a diagram explaining the data collection operation by theanalyzing system of the second embodiment.

BEST MODES FOR CARRYING OUT THE INVENTION

The analyzing system according to the present invention can be appliedto various kinds of analyzing systems. Hereinafter, two specificexamples are described. In the first embodiment, the analyzing systemaccording to the present invention is applied to a preparativeseparation system, and in the second embodiment, it is applied to anoverlap injection data collection system.

FIRST EMBODIMENT

FIG. 1 is a schematic diagram of the main components of the preparativeseparation system 1 according to the present embodiment.

The preparative separation system 1 includes, as the units forpreparative operations: a supply pump 11 for sucking a mobile phase (ora carrier) from a mobile phase container 10 and sending it out at aconstant flow rate; an auto sampler for selectively collecting samplesin a predetermined order from a number of liquid samples prepared on arack, performing a pretreatment such as a condensation according tonecessity, and then injecting the samples into the mobile phase whichhas been supplied from the supply pump 11; a column 13 for temporallyseparating the liquid samples supplied with the mobile phase intocomponents; a column oven 14 for controlling the temperature of thecolumn 13; a detector 15 for detecting the sample components which havebeen separated by the column 13; and a preparative separation unit 16for putting each component detected by the detector 15 into differentcontainers. These units are controlled by a controller 18 based on theinstructions from a personal computer (PC) 20.

One of the characteristic features of the present embodiment is a piping17, which is provided between the detector 15 and the preparativeseparation unit 16 so as to delay the arrival of sample components fromthe detector 15 at the preparative separation unit 16 for apredetermined time. In addition, the controller 18 includes an executiontime computation unit 19 for storing a point in time which serves as thebase point for a processing in the preparative separation unit 16, andfor computing the execution time of starting/finishing the preparativeoperation in the preparative separation unit 16 based on the base-pointtime and the shift time data which are added to the instruction ofstarting/finishing the preparative operation sent from the PC 20.

The operation control of each unit through the controller 18 and thedata processing are performed by executing a dedicated dataprocessing-operating program which has been installed in the PC 20. Inthe preparative separation system 1 of the present embodiment, the PC 20functions not only as function blocks for ordinary data processing andoperation control, but also as a delay time computation unit 21, a peakdetection unit 22, and a shift time computation unit 23. The specificoperations of the units 21 through 23 will be described later.

An input unit 24, which is an input device such as a keyboard and amouse, and a display 25 such as a cathode ray tube (CRT) display or aliquid crystal display (LCD) are connected to the PC 20.

Hereinafter, the operation of the preparative separation system 1 of thepresent embodiment is described.

Before starting a preparative separation operation, a user provides thePC with a variety of parameters such as the temperature of the columnand the flow rate of the pump. In the preparative separation system 1 ofthe present embodiment, the user also provides the volume of the piping17 as another parameter. The delay time computation unit 21 computes thetime required for a sample component to arrive at the preparativeseparation unit 16 from the detector 15 based on the volume of thepiping 17 and the flow rate of the pump. Hereinafter, the period of timerequired for a sample component to arrive at the preparative separationunit 16 from the detector 16, which is computed by the delay timecomputation unit 21, will be referred to as the traveling time ta.

After all the parameters required for the preparative separationoperation have been provided and an the instruction of starting thepreparative separation operation is provided to the PC 20 by the user,the PC 20 instructs, through the controller 18, the auto sampler 12 toinject the sample. Upon receiving this instruction, the auto sampler 12performs a predetermined pretreatment and injects the sample into themobile phase. At the point in time when the sample is injected into themobile phase, the auto sampler 12 informs the controller 18 of thisevent.

The controller 18 calculates, as the retention time, the time elapsedfrom the point in time when the sample was injected into the mobilephase (hereinafter, this time will be referred to as the “sampleinjection time”), adds the data of the retention time to each piece ofthe detection signal data which are continuously sent from the detector15, and sends them to the PC 20. The execution time computation unit 19stores the sample injection time as the base-point time. Hereinafter,the sample injection time (base-point time) will be denoted by Ts.

The peak detection unit 22 of the PC 20 creates a chromatogram based onthe data of the detection signal and the retention time which are sentfrom the controller 18, and obtains the retention time when a peak isdetected based on the level of the detection signal and the shape ofupslopes and downslopes. In the following description, assume that therise of a peak (initial point) has been detected at the retention timetb.

The shift time computation unit 23 adds the traveling time ta, which wascomputed in advance by the delay time computation unit 21, to theretention time tb. That is,

tb′=ta+tb

-   is computed. The time tb′ is a relative time based on the point in    time at the retention time “0” (i.e. the sample injection time), and    is independent of the time in the PC 20. Therefore, the time tb′    itself can be used as the shift time for the point in time when the    initiation of the preparative separation operation is executed.

The PC 20 sends a fractionation initiation operation instructiontogether with the shift time tb′ to the controller 18.

When the controller 18 receives the fractionation initiation operationinstruction from the PC 20, the execution time computation unit 19 addsthe shift time tb′ to the previously stored sample injection time Ts,and sets

Tsb=Ts+tb′=Ts+ta+tb

-   as the execution time of the fractionation initiation operation in    the preparative separation unit 16. The controller 18 stands-by by    the execution time which has been set. At the execution time, the    controller 18 makes the preparative separation unit 16 execute the    fractionation initiation operation.

Rather than making the controller 18 stand-by the operation, thefractionation initiation operation may be instructed to the preparativeseparation unit 16 in advance designating the execution time.

Thus far, the process regarding the fractionation initiation operationhas been described. The same or similar process may be taken for thefractionation termination operation.

In the preparative separation system 1 of the present embodiment, the PC20 provides the execution time of the fractionationinitiation/termination operation as a relative time to the controller18. Therefore, even in the case where the time of the PC 20 and that ofthe controller 18 are not synchronized, the controller 18 can accuratelyset the execution time of fractionation initiation/termination operationwhich will be performed in the preparative separation unit 16. If thepiping 17 is placed so that the traveling time of sample components issufficiently larger than the delay time of signals due to the signaltransfer lag and other reasons, the delay time can be absorbed, allowingthe units to cooperate with each other at a correct timing.

SECOND EMBODIMENT

An overlap injection data collection system 2, which is the secondembodiment of the analyzing system according to the present invention,is described with reference to FIG. 2.

The overlap injection is a method in which, while a sample is beinganalyzed and before the analysis of this sample is completely finished,the next sample is injected from an auto sampler in order to increasethe throughput of the analysis.

However, the pretreatment time by the auto sampler varies depending onthe method settings, and the time required to inject a sample variesdepending on the position of the vial and other factors. Therefore, itis difficult to predict when the sample is injected.

In addition, in a chromatograph analysis, a series of data processingsas follows is usually performed for one sample: (1) data file creation,(2) data collection, (3) data file saving, (4) data analysis, and (5)report output. Performing an overlap injection causes a problem that thedata processings for the two successive samples overlap each other,complicating the processing flow.

FIG. 2 schematically shows the main components of the overlap injectiondata collection system 2 (which will be hereinafter simply referred toas the “system 2”) of the present embodiment. The system 2 includes, asthe units for performing a chromatograph analysis, a mobile phasecontainer 10, a supply pump 10, an auto sampler (sample injector) 12, acolumn (separator) 13, a column oven 14, and a detector 15. These unitsare controlled by a controller 18 based on the instructions from apersonal computer (PC) 20.

The controller 18 has a data collection instruction unit 30 forinstructing the PC 20 at a predetermined timing to start collecting thedata of the next sample.

The PC 20 controls each unit through the controller 18 and performs adata processing by executing a dedicated data processing-controllingprogram which has been installed in the PC 20. In the system 2 of thepresent embodiment, the PC 20 functions not only as function blocks fordata processing and operation control for a conventional overlapinjection, but also as a buffer unit 31, a sample injection instructionunit 32, and a ready state notification unit 33. The specific operationsof the units 31 through 33 will be described later.

An input unit 24, which is an input device such as a keyboard and amouse, and a display 25 such as a cathode ray tube (CRT) display or aliquid crystal display (LCD) are connected to the PC 20.

Hereinafter, the operation of the system 2 of the present embodimentwill be described with reference to FIG. 3, which is an explanationdiagram of the processing by the system 2. FIG. 3 shows the case wherethe analyses of samples A and B overlap each other. With the point intime when each sample is injected being designated as 0, it is possibleto predict from the analysis conditions and other factors that no peakappears between the time 0 and t0 and peaks appear only between the timet0 and te.

Before starting an analysis, a user provides the PC with a variety ofparameters such as the temperature of the column and the flow rate ofthe pump. After all the analysis conditions are provided and the userinstructs the PC 20 to start the analysis, the PC 20 first creates adata file for the sample A. Then, the PC 20 instructs the auto sampler20 to inject the sample. Upon receiving this instruction, the autosampler 12 performs a predetermined pretreatment, and injects the sampleA into the mobile phase. At the point in time when the sample isinjected into the mobile phase, the auto sampler 12 informs thecontroller 18 of this event.

The controller 18 sets the point in time when the sample A was injectedinto the mobile phase as T=0, calculates the time elapsed from thatpoint in time, adds the data of the elapsed time T to each piece of thedetection signal data which are continuously sent from the detector 15,and sends them to the PC 20. The data of the detection signal and thoseof the elapsed time T (which will hereinafter be referred to as the“detection data”) are temporarily stored in the buffer unit 31.

The PC 20 sequentially reads the detection data stored in the bufferunit 31 from the point in time T=0, and writes the data one afteranother in the data file created for the sample A (FIG. 3).

At the point in time of T1=te−t0, the sample injection instruction unit32 instructs the auto sampler 12 through the controller 18 to inject thenext sample B. The auto sampler 12 performs a predetermined pretreatmentto the sample B and injects the sample B into the mobile phase (at thepoint in time of “INJ” in FIG. 3). When the sample B is injected intothe mobile phase, the auto sampler 12 informs the controller 18 of thisinjection. The data collection instruction unit 30 of the controller 18receives this notification and memorizes the point in time of theinjection.

Even after the injection of the sample B, the PC 20 continues to writethe data in the data file for the sample A through the buffer unit 31,and finishes writing the data at the point in time of T2=te. Then, thePC 20 performs the processings such as saving the data file, analyzingthe data, and outputting a report.

After finishing the report output for the sample A, the PC 20 creates adata file of the sample B. Then, the PC 20 sends a ready statenotification, which signifies that the preparation for the datacollection of the sample B has been finished, to the data collectioninstruction unit 30 of the controller 18 from the ready statenotification unit 33.

Upon receiving the ready state notification, the data collectioninstruction unit 30 computes the period of time (i.e. ts) elapsed fromthe point in time when the sample B was injected (at the point in timeof the retention time 0 of the sample B) to the point in time when thedata collection instruction unit 30 received the ready statenotification (assuming that this point in time is at the retention timets of the sample B). The data collection instruction unit 30 adds theinstruction of data collection operation for the sample B and theelapsed time ts from the injection of the sample B to the data of thedetection signal at this point in time as well as the data of theelapsed time T (=T3), and sends these data to the PC 20.

Upon receiving the instruction of data collection operation from thedata collection instruction unit 30, the PC 20 reads out the detectiondata between the point in time going back by the time period is from theelapsed time T3 (i.e. T3−ts) of the detection signal, which have beensent together with the instruction, and the point in time of T3, andthen writes the data in the data file for the sample B (the hatched areain FIG. 3). After that, the PC 20 continues to write the data after thepoint in time T3 in the data file through the buffer unit 31 as in theconventional manner This operation is performed by the point in time ofT5=T3−ts+te so that the time period of the written data corresponds tothe retention time to of the sample B. Then, the PC 20 finishes writingthe data for the sample B in the data file, saves the data file,analyzes the data, and outputs a report.

If there is a sample (e.g. sample C) to be measured after the sample B,the sample injection instruction unit 32 provides the instruction ofinjecting the sample C at the point in time of T4=T3−ts+te−t0, whichcorresponds to the retention time t3−t0 of the sample B. Then, the sameoperation as for the sample B will be performed.

As just described, the present system 2 can perform a series ofoperations for one sample such as: (1) creating a data file, (2) writingdata, (3) saving the data file, (4) analyzing the data, and (5)outputting a report, while performing an overlap injection. Theseoperations can be performed without overlapping the operations foranother sample, and the order of the series of operations can remainunchanged for the next sample to be analyzed.

The analyzing system according to the present invention has beendescribed by using embodiments. It should be noted that the embodimentsdescribed thus far are merely an example, and it is evident that anyappropriate modification, adjustment, or addition can be made within thespirit of the present invention.

In the second embodiment, the instruction of injecting the next sampleis performed by the sample injection instruction unit 32 at the point intime of the retention time t3−t0 of the sample that is being analyzed.However, taking into consideration the time required for thepretreatment in the auto sampler 12, the injection instruction may beprovided at an earlier timing. Although it is difficult to previouslyknow the time for a pretreatment because it varies depending on thesample, it is possible to predict the minimum time required for thepretreatment. Therefore, providing the injection instruction earlier bythe minimum time can increase the throughput of the analysis.

EXPLANATION OF NUMERALS

1 . . . Preparative Separation System

2 . . . Overlap Injection Data Collection System

10 . . . Mobile Phase Container

11 . . . Supply Pump

12 . . . Auto Sampler (Sample Injector)

13 . . . Column (Separator)

14 . . . Column Oven

15 . . . Detector

16 . . . Preparative separation unit

17 . . . Piping

18 . . . Controller

19 . . . Execution Time Computation Unit

20 . . . Personal Computer (PC)

21 . . . Delay Time Computation Unit

22 . . . Peak Detection Unit

23 . . . Shift Time Computation Unit

24 . . . Input Unit

25 . . . Display

30 . . . Data Collection Instruction Unit

31 . . . Buffer Unit

32 . . . Sample Injection Instruction Unit

33 . . . Ready State Notification Unit

1. An analyzing system comprising: a commanding unit for sending acommand; and an executing unit for, upon receiving the command,executing a processing, wherein the commanding unit computes a shifttime which is a difference between a predetermined base-point time inthe executing unit and an execution time of the processing for which thecommand is sent to the executing unit, and sends the computed shift timewith the command for the processing to the executing unit, and theexecuting unit executes, at a point in time before or after thebase-point time by the shift time, the processing indicated by thecommand received with the shift time.
 2. The analyzing system accordingto claim 1, comprising: a sample injector for sequentially injecting aplurality of samples; a separation unit for separating the injectedsample into different components; a detector for detecting the separatedsample components; a data collection instruction unit, which functionsas the commanding unit, for computing an elapsed time, which is regardedas the shift time, from a point in time when the sample injector startedan injection of the samples to a predetermined time; and a dataprocessing unit, which functions as the executing unit, for performing apredetermined data processing for each of the sequentially injectedsamples, wherein the data processing unit comprises: a buffer unit forsequentially memorizing detection data provided from the detector; asample injection instruction unit for instructing the sample injector toinject a next sample; and a ready state notification unit for notifyingthe data collection instruction unit that a preparation for a datacollection of the next sample has been finished, the data collectioninstruction unit sends, upon receiving the notification from the readystate notification unit, an elapsed time from a point in time when theaforementioned next sample was injected together with an instruction ofdata collection of the aforementioned next sample to the data processingunit, and the data processing unit reads out the detection data storedin the buffer unit going back by the elapsed time from a point in timewhen the instruction sent from the data collection instruction unit isreceived and starts a data collection of the aforementioned next sample.3. The analyzing system according to claim 1, comprising: a sampleinjector for injecting a sample into a chromatograph; a detector fordetecting sample components separated by the chromatograph; apreparative separation unit, which functions as the commanding unit, forfractionating the sample into components and putting each component in adifferent container; a control unit, which functions as the commandingunit, for controlling the preparative separation unit; and a piping forcarrying the sample components from the detector to the preparativeseparation unit in a predetermined traveling time, wherein the controlunit refers to a chromatogram created based on detection data from thedetector to determine a retention time at which a peak is detected, andsets a time in which the traveling time is added to the retention timeto be the shift time, and the preparative separation unit sets a pointin time when the sample injector injects the sample into thechromatograph to be the base-point time, and sets a time point in timewhen the shift time has passed from the base-point time to be theexecution time for starting or finishing the fractionation.
 4. Theanalyzing system according to claim 3, wherein an amount of the pipingis provided as a parameter to the control unit, and the control unitcomputes the arrival time based on the amount and a flow rate of acarrier of the chromatograph.